Poor Fuel Economy

Definition: Fuel economy, as measured by an actual road test, is noticeably lower than expected. Also, economy is noticeably lower than it was on this vehicle at one time, as previously shown by an actual road test.

^ Check owners driving habits.

- Is A/C on full time (Defroster mode on)?

- Are tires at correct pressure?

- Are excessively heavy loads being carried?

- Is acceleration too much, too often?

- Suggest driver read "Important Facts on Fuel Economy" in Owner's Manual.

^ Perform "Diagnostic Circuit Check - Calif".

^ Perform the "System Performance Check - Calif".

^ Check air cleaner damper door operation.

^ Check air cleaner element (filter) for dirt or being plugged.

^ Check for proper calibration of speedometer.

^ Visual (Physical) Check:

- Vacuum hoses for splits, kinks and proper connections as shown on Vehicle Emission Control Information label.


- Ignition wires for cracking, hardness and proper connections.


^ Check ignition timing. See Vehicle Emission Control Information label.


^ Check EST operation, Chart C-4C.


^ Remove spark plugs. Check for cracks, wear, improper gap, burned electrodes or heavy deposits. Repair or replace as necessary.

^ Check compression.

^ Check TCC for proper operation. See Chart C-8. Use ALCL tool if available (Calif.).

^ Check for dragging brakes.

^ Suggest owner fill fuel tank and recheck fuel economy.

^ Check for exhaust system restriction.